Elevator systems are normally equipped with a separate pair of guide rails mounted in the elevator shaft for each of the elevator car and the counterweight to guarantee the safe and independent run of the elevator car and the counterweight. The provision of two pairs of guide rails necessarily takes up considerable space within the cross-sectional area of the shaft which could otherwise be more usefully occupied by the elevator car. Furthermore, two pairs of guide rails represent a considerable expense because of the required material, the necessary assembly and the cost of regular inspection and maintenance particularly for high-rise elevator installations.
Publication DE-A1-44 23 412 discloses a guiding arrangement with only one pair of guide rails comprising two single T-shaped rails arranged side by side so that the cross members of both T-shaped rails are aligned. The cross members of the “T”s in turn constitute an inner-located pair of guiding blades for the counterweight and an outer-located pair of guiding blades for the elevator car. Thus, although unified in T-shaped rails, this system still requires separate guide surfaces or blades for the elevator car and the counterweight respectively.